This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The main goal of this project is to elucidate the functions of the KIN3 protein kinase in Saccharomyces cerevisiae. KIN3 is the S. cerevisiae member of the NIMA family of protein kinases, one of the most poorly understood families of mitotic protein kinases. The family appears to be among the least functionally conserved mitotic regulators, having been implicated in chromosome condensation in fungi and spindle formation in metazoans. The experimental plan includes: (1) The characterization of the effects of deletion of Kin3, a nonessential gene, by fluorescence microscopy, analysis of effects on cell cycle progression, and drug sensitivity tests;and (2) Identification of genes that interact with Kin3 by high-throughput synthetic genetic analysis. These studies will aid in understanding the functions of the highly variable NIMA protein kinase family to which KIN3 belongs and will provide significant information regarding the roles of the NIMA family of protein kinases in mitotic regulation.will provide significant information regarding the roles of the NIMA family of protein kinases in mitotic regulation.